Washing apparatus



March 26, 1935. J, H. CLARK 1,995,635

WASHING APPARATUS Filed May 2, 1933 2 Sheets-Sheet l Fi gl.

Inventor": Jesse H. Clark,

bM Wwm H is Attorney.

March 26, 1935... J. H. CLARK WASHING APPARATUS Filed May 2, 1933 2Sheets-Sheet 2 7 Al Md? Inventor: Jesse H. C lark His Attcvheg.

Patented Mar. 26, 1935 WASHING APPARATUS Jesse H. Clark, Cicero, Iil.,assignor to Walker Dishwasher Corporation,

Delaware a corporation of Application May 2, 1933, Serial No. 668,995

14 Claims.

My invention relates to washing apparatus, more particularly todishwashing apparatus, and has for its object the provision of improvedapparatus of this character.

More specifically, the invention relates to dish- Washing apparatuswherein a cleansing fluid, such as water, is circulated in a washing vatthrough dish supporting racks by suitable power driven means, such as amotor driven impeller,

and has, as one of its objects, the provision of improved means forsupplying the washing.vat with a predetermined quantity of cleansingwater so that the most eiiicient cleansing action will be effected.

In carrying out the invention, suitable conduit means are provided forsupplying the washing vat with a cleansing fluid. A predeterminedquantity of fluid for a subsequent washing operation is provided byallowing a measured quantity of the fluid supplied to the vat toaccumulate in it. In one form of my invention, the vat is provided Wth adrain port which is controlled by means of a suitable valve. Means areprovided for controlling the operation of the drain valve to regulatethe drainage of fluid from the vat responsively to a condition ofoperation of the fluid circulating means so as to prevent theaccumulation of more than a predetermined quantity of fluid in the vat.In this form of the invention, the drain valve is operated in accordancewith the load imposed on the motor driving the fluid circulating meansby means of a thermostat which is heated in accordance with themagnitude of the motor load current so that d when the load imposed onthe motor attains a predetermined value, the valve is opened to allowsome of the water to drain from the vat,

whereas when the load on the motor falls to a predetermined low valuethe drain valve is closed.

In this manner, the quantity of water which will be allowed to remain inthe vat will be a mean between the maximum and minimum quantities atwhich the valve opens and closes.

In another form of my invention, a suitable pump is provided to drawwater from the vat and to discharge it into a drain. This pump isprovided with an operating motor which is controlled in accordance withthe load imposed on the fluid circulating motor so that when this loadattains a predetermined maximum value, the pump will be started so as todischarge some of the water from the vat, whereas, when the load fallsto a. predetermined low value, the pump will c ase to function towithdraw any more water 1 the vet. Here also, the pump is controll tothe -..agnitude of the load current of the fluid circulating motor.

The invention also contemplates the provision of improved thermostaticstructure which, as

=y means of a thermostat which respondspreviously pointed out, isarranged to control the valve and the pump of the above mentioned formsof the invention responsively to the load current of the fluidcirculating motor. In accordance with the invention, the thermostatcomprises a pair of opposed bi-metallic bars, each of which is providedwith a portion movable in response to changes in temperature;preferably, the bars will be arranged so that one end of each bar moveslaterally and, preferably, so that the two ends of the bars move in thesame plane. An elastic member is arranged to bear on the movableportions of the thermostatic bars so as to cause these bars to movequickly from one controlling position to another.

For a more complete understanding of the invention, reference should behad to the accompanying drawings in which Fig. 1 is a fragmentaryelevation of dishwashing apparatus embodying the invention, portionsbeing shown in section and portions being broken away so as toillustrate certain structural details; Fig. 2 is an elevation in sectionof a temperature responsive control dc.- vice used in the apparatus ofFig. 1 and arranged in accordance with the invention; Fig. 3 is a planview of the thermostatic control device of Fig. 2, with portions removedso as to illustrate certain structural details; Fig. 4 is a diagrammaticrepresentation of certain elements of the washing apparatus of Fig. 1,and illustrating certain control mechanism for the apparatus includingthe temperature responsive device shown in Figs. 2 and 3; Fig. 5 is aview similar to Fig. 4 but showing a temperature control device ofmodified form; Fig. 6 is a fragmentary view in elevation, of dishwashingapparatus embodying a modified form of the invention, portions beingshown in section and portions broken away so as to illustrate certainstructural details; Fig. '7 is a diagrammatic view illustrating certainelements of the dishwashing apparatus of Fig. 6, together with certaincontrol mechanism therefor; and Fig. 8 is a view similar to Fig. '7, butillustrating a modifled form of control mechanism for the apparatus.

Referring to Fig. 1, the invention is shown as applied to dishwashingapparatus comprising a washing vat 10 for receiving dishes and likeutensils to be cleansed, and also some suitable washing fluid, such ashot cleansing water. The vat 10 is provided with an invertedfrusto-conical bot,- tom wall 11, preferably formed integrally with theside walls of the vat. While the vat, together with its bottom wall, maybe made of any suitable material, preferably they will be formed of somesuitable metal, such as a rust-resisting steel, which preferably will beplated or enameled.

It will be understood that the washing apparatus will be provided withsuitable trays or basketsarranged within the vat to receive and supajtha u e biaees be jgiven'a shape such that a cl ansing fluid in ','thelower portion of the vat It will also be understood that thewashingvat-L will be supported in a .vertical position, as, shown inFig. 1, by any suitahlemeans (not shown).

In the lower portionofithei'vat l .andpreferably arranged so as to besubstantially embraced by the bottom wall 11, is a suitable impeller 12which is driven by an electric motor l3 c arried by the bottorn wall 11on the exterior of the vat.

It will be, understood that the impeller will rovided with suitableblades, which may have suitable shape; the important feature 'being willbe thrown x upwardly and outwardly'in an efficient manner through thedish supporting trays the rotary'fmotion'of the impeller. The l n pellerfwill' be "formed from any suitable mate irial' 'such'as'cast aluminumor pressed steel.

' The motor 13 'is supported 'by means of a suit f'able bushing 14 whichis passed through an erlture15i provided for it in the bottom wall ofthe: vat andpreierably' arrangedcentrally of the vat. The bushing 14, asshown, is provided with a flange 16 which rests on a flange 17surrounding .t he opening 15 and formed from the'mater ial of thebottornwall ofthevat,

Themotor .13, isoperably connected with the j iiiii ner 12 by m an f 1 hft w i h i d frect dt o shi bushing 14. Water, orother suitablecleansing fluid, is supplied to the vat throughaconduit 20 whichQasshownis'directed through the bottom wall of the ;v at This conduit 20communicates with a ringshapedconduit2'1 resting on the bottom wall '11.

This conduit communicates with a plurality of iter tically arrangedconduits 22. The upper ends of these conduits turn inwardly toward thecentralvertical a ris o'f the vatwhere'they termi nate in a verticallyarranged conduit 23. This conduit communicates at its upper end with asuitable reaction spray device 24. This means for supplying the water tothe vat, including the conduit 21, the vertically arranged conduits 22,the conduit 23 .and thereaction spray device24, are

described and claimed in my copending application, Serial No. 653,243,filed January 24, 1933,

and, assigned to the same assignee as this inven- Arrangedin t lower walin of the at is a drain port 26 which is provided with a control- ,lingvalve 27. The. drainport 26 communicates witha discharge..ordrain,conduit 28 which, as shown in; Fig. 1, constitutes the intake of asuit able pump 30. The pump 30 discharges into a drain .conduit 31 whichmay be directed to any :s'uitabledrain such as an ordinary kitchen sink.

The pump .30 is provided with an impeller 32 which ismechanicallyconnected with the motor Thus, the motor ing. lever 34 which ispivotally mounted on suitable. brackets 35 carried by the walls of thecon- Attached to one end duit 28,-asshown in Fig. 1, I of the arm 34 isatension. spring 36 which, as shown,,is arranged to bias the valve 27 toits closed position .A suitable rod 36a is also attachedto the lever34so that the valve can be manually operated. The lower end of this rod.

ismecha'nically connected to the lever 34 so that when theoperating coilof the electro-magnet is energized to retract the armature the valvewill be moved to its open position.

The. energization of the electro-magnet 37 is controlled in accordancewith the load imposed on the impeller 12 in circulating fluid in thevat, more specifically in accordance with the magnitudeof the armaturecurrent of motor 13. The "electro magnet is controlled so that when apredetermined quantity of water has been supplied to the vat and hencewhen the load imposed on th'ejmotor attains a predetermined magnitude,th'e electro-magnet will be energized to open the va'1ve'27 so as toallow water to be withdrawn from the vat, whereas when the quantity ofwater in the vat falls to a predetermined low magnitude', i; e., whenthe load on the motor 13 falls to a predetermined low value, theelectro-magnet will be deenergizedso as to allow the valve to moveto itsclosed position under the influence of its spring 36.

In order to control the energization of the electro m'agnet inaccordance with the armature current of the impeller driving motor 13, asuitable temperature responsive means is provided which is'arranged tobe included in the armature circuit of the motor so that the temperatureresponsive element of the device is actuated in accordance with themagnitude of the armature current.

as shown diagrammatically in Fig. 4, the motor '13, which is of theseries type, is provided with'a suitable source of electrical supply 40.motor is connected with the supply source by'm'eans of conductors 41; asshown in Fig. 4, a suitable controlling switch 42 is arranged in theseconductors between the supply source and the motor.

The armature circuit of the motor, as shown, includes the temperatureresponsive device 43. This device is shown in detail in. Figs. 2 and 3.As there shown, the device comprises a pair of bi-metallic bars 44 and45 mounted on a suitable base 46. Each of these bars is made of twostrips of metal having dissimilar temperature coemcients of expansion,such as brass and invar, the 'two strips being secured togetherlengthwise inany suitable manner. The bar 44 is rigidly, secured at oneend to the support 46 by means of clamping screws 47 passing throughsuitable holes provided for them in the bar, while the other, end of thebar is free to move laterally in response to changes in temperature. Thebar 45 likewise is rigidly secured at one end to the base 46 by means ofsuitable clamping mem bers 48, and this bar also has one end free tomove laterally in'response to changes in temlperature) As shown in Fig.2, the two bars 44 3 and 45 are substantially in the same plane andfithe free ends of the bars are arranged to move jlaterally in the sameplane.

Bearing on the movable ends of the bars is a U- shaped resilient memberor spring 50, which, as shown has one arm bearing on the movable end ofthe bar 44 and its other end bearing on the movable end of the bar 45.The spring member 50 is pivotally mounted on a supporting bracket 51; inorder to effect this mounting, the base of the spring is rigidly securedto a bracket 52 which is pivoted to the bracket 51 by means of a pin 53.The arms of the bracket 51, as shown, are provided with elongated slots54 which receive the pivoting pin 53 so that the bracket 52 can havelimited lengthwise movement relative to the bracket 51.

Each of the bi-metallic bars 44, 45, together with the U-shaped springmember 50, constitutes a thermostat which is arranged in accordance withthe temperature control device described in the United States Patent toA. H. Simmons, No. 1,743,073, dated January '7, 1930.

The base of the spring 50 carries a suitable switch actuating arm 55,which is arranged to actuate a pair of switch contacts 56 and a con tact57. These contacts are carried on opposite ends of a resilient contactarm 58 which is also secured to the base of the spring 50. The resilientarm 58 is arranged above the actuating arm 55, and as shown in Fig. 2,bears away at its end from the actuating arm.

The contacts 56 cooperate with a pair of fixed contacts 60 supported onstandards 61 attached to the base 46, while the contact 57 cooperateswith a fixed contact 62 supported by means of a standard 63 also securedto the base 46.

It will be understood that when the bars 44 and 45 are cold, they willoccupy their respective positions shown in Fig. 2. In other words, thetension in the bars will be such that when the bars are cold thecontacts 5'1 and 62 will be closed, while the contacts 56 "and 60 willbe opened. It will also be understood that each blade when heated isarranged to move upwardly from the base 46, i. e., toward the left, asviewed in Fig. 2.

When the blades are cold, it will be observedthat the pivot bearingbetween the blade 44 and the U-shaped spring member 50 lies below aneutral line that contains the point of support 4'7 for the bar 44 onthe base 46 and the pivot 53, whereas the pivot bearing between the bar45 and the spring 50 will be above a neutral line joining the point ofsupport 48 of the bar 45 and the pivot bearing 53. It will also beobserved that when the bars 44 and 45 lie in their respective neutrallines at the same time, they will be in a position of unstableequilibrium so that any further upward movement of either will snap thatbar to its other controlling position. That is, when the two planescontaining the two bars 44 and 45, respectively, have the same relativeposition with respect to the spring 50 the bars will be in theirunstable positions.

Thus, when the bar 44 is heated so that it tends to move upwardly, theinitial portion of its movement, i. e., from its position shown in Fig.2 to the neutral position, will be resisted by the resilient member 50and the tension in the bar 45. As the bar moves upwardly toward itscritical position, the force exerted by the spring rapidly decreasesuntil, when the bar is in the critical position, the force exerted bythe spring will be substantially in the direction of the line of supportof the thermostat and will have no controlling action on the movement ofthe thermostat. In other words. the spring decreasingly ret-he movementof the thermostat and, as a result. the thermostat rapidly acceleratesand moves a high speed through the neutral position the opposite sidethereof. During this movement of the thermostatic bar 44, the springwill rotate somewhat on its pivot 53 and the other thermostat bar 45will be moved downwardly to a position below its neutral line betweenthe point of support 48 and the pivot 53.

The foregoing operation of the temperature responsive device results ina quick opening of the contacts 57 and 62 and a quick closing of thecontacts 56 and 60.

By reason of the fact that the contact 57 is carried on the spring 58,which normally bears away from the actuating arm 55, the contacts 57 and62 will remain closed substantially until the instant the contacts 56and 60 are closed, i. e., substantially until the instant the thermostatbar 44 snaps through its neutral position. It will be observed that thecontacts 56 and 60 also will be closed substantially at the instant thebar 44 snaps through the neutral.

As long as the bar 44 is heated, the contacts 56 and 60 will be closedand the contacts 57 and 62 will be open. It now the thermostatic bar 44is allowed to cool, and thermostatic bar 45 is:

heated, the latter bar will tend to move upwardly through its neutralposition and upon the occur rence of a predetermined maximum temperaturewill move through its neutral. This opera ion will open the contacts 56and 60 and will close contacts 57 and 62.

Adjustment of the temperature setting of the thermostat is effected bychanging the tension of the spring member 50. This is accomplished byproviding an adjustable point of support for one of the bars 44, 45. Asshown, the bar 45 is at tached to a. support 64 that is mounted in achannel 64a in the base 46 for movement toward and away from the spring50. ,The position of the bar is adjusted by means of a screw 65. It willbe understood that when the bar 45 is moved inwardly the tension of thespring member 50 will be increased whereby the temperature setting ofthe thermostat will be increased, whereas when the bar is moved awayfrom the spring member so as to decrease its tension, the temperaturesetting will be reduced. When the tension in the spring 50 is changed toadjust the temperatu e setting of the device, the distance between thelegs of the U is changed. This, of course, changes the position of thepin 53. The elongated slots 54 provide for this shifting of the pin 53.

Suitable binding posts 66 and 67 are provided for the fixed contacts 60and 62 respectively, and similar binding screws 68, 69 and '70 areprovided for anchoring the electrical connections directed to thethermostat.

It is contemplated that the bi-metallic bars 44 and 45 will be heated bythe armature current of the impeller driving motor 13 and, as shown,each bar will be formed of a number of convolutions 44a, 45a,respectively, so that a relatively long path for the current is providedin the thermostat. As shown, the convolutions of the thermostat 44terminate in the two outside supporting screws 47 which also function asbinding posts, and likewise, the ends of the convolutions of thebi-metallic element 45 terminate in the outside clamping screws 48,which also serve as binding posts. It will be understood that theeifective length of the thermostat bars will be such that an electricalresistance will be provided to give the desired heating of the blades.

As clearly shown in Fig. 2, the free ends of the bars which bear on thespring 50 are electrically insulated from the remainder of the bars thatcarry current by means of insulating strips 71 which will be formed ofany suitable electrically insulated material, such as a phenoliccondensation product.

As shown diagrammatically in Fig. 4, one terminal ofthe motor isconnected through one conductor 41 to the lower conductor of the supplysource 40, whereas the other terminal of the motor is electricallyconnected to one end of each of the thermostatic bars 44 and 45. Theother end of the thermostatic bar 44 is electrically connected through aconductor '72 to the terminal 62 of the thermostat while the remainingterminal of the thermostatic bar 45 is electrically connected to one ofthe fixed contacts 60 of the thermostat through a conductor 73. Theother terminal 60, as shown, is electrically connected with one side ofthe operating coil of the electro-magnetic device 37 through a conductor74, the other side of the device 37 being electrically connected withthe lower conductor of the supply source 40 through one of theconductors 41. The upper conductor of the supply source 40 iselectrically connected through the other conductor 41 with the contacts56 and c7 of the thermostat. As shown, this conductor is electricallyconnected with the strip 58 that carries these contacts.

It will be understood that in the operation of the washing apparatus,the controlling switch 42 will be closed so as to energize the impellerdriving motor 13 through a circuit which may be traced from the lowerconductor 40 of the supply source through the conductor 41, the armatureand field windings of the motor 13, the thermostatic bar 44, theconductor 72, the closed contacts 57 and 62, and then through theresilient switch arm 58 to the upper conductor of the supply source 40.As a result of these connections, the motor 13 will be energized so asto rotate the fluid circulating impeller 12 and also to operate thedrainage pump 30. The drain valve 27 will then be closed by means of theoperating rod 36a and the water will be turned on from any suitablesupply source that communicates with the conduit 20. The water suppliedto this conduit flows into the vat through the conduits 22 to thereactionary device 24. The water issuing from this device is hurled overand about the dishes supported in the vat, and eventually finds its wayinto the lower portion of the vat where it is allowed to accumulate.

As the water continues to flow into the vat, it imposes an increasingload upon the impeller driving motor 13 and, as a result of this, thearmature current of the motor increases. This increase in the armaturecurrent increases the temperature of the thermostatic bar 44 untileventually, when a predetermined maximum quantity of water has beensupplied to the vat, the armature current will be such that thethermostatic bar 44 will be heated to operate as previously described toclose the contacts 56 and 60 and to open contacts 57 and 62. Thisoperation disconnects the armature of the motor circuit from thethermostatic bar 44 and connects it to the supply source through thethermostatic bar 45. This operation also connects the operating coil ofthe electro-magnetic device 3'? with the supply source through a circuitincluding the lower conductor of the supply source, the conductor 41connected therewith, the operating coil of the device 37, the lower oneof the contacts 60, the switch member 58, and the other conductor 41connected to the upper conductor of the supply source.

This operation will energize the electro-niagnetic device 37 so as toopen the drain valve 27.

and thereby allow water to flow from the vat into the pump 30 which, aspreviously described, will discharge the water into the drain 31.

After the thermostat has thus operated, the thermostat bar 44 will beginto cool and the thermostatic bar 45 will begin to heat up. In arelatively short period of time, which will be determined somewhat bythe load upon the motor 13 which will be decreasing as the water iswithdrawn from the vat and also upon the setting of the thermostat 43,i. e. the tension in the spring 50, the bar 45 will be heatedsufficiently to move upwardly through its neutral position whereby thecontacts '7 and 62 will be closed and the contacts 56 and 60 will beopened. This operation will deenergize the electro-magnetic device 3'7so as to allow the valve 27 to be closed by its spring 36; and the motor13, as before, will be energized through the thermostatic bar 44. Thethermostat will be set so as to operate to close the valve 27 when thequantity of water in the vat has been reduced to a predetermined lowvalue.

If the supply source continues to feed water into the vat, the abovedescribed cycle of operation will be repeated, 1. e., when apredetermined maximum quantity of water has accumulated in the vat, thevalve 27 will be opened to allow a quantity of the water to be withdrawnfrom the vat, whereas when the quantity in the vat has been reduced to apredetermined minimum, the valve 27 will be closed. In this manner, whenwater is flowing into the vat the control system will function so as tooperate the valve 27 between its closed and open positions so as toallow but a predetermined quantity to accumulate in the vat.

It will be understood that when the valve 2'7 has been opened to allowwater to flow from the vat, the flow of water in the drain willconstitute a signal to the attendant that the proper quantity of waterhas been supplied to the vat. If the conduit 31 be connected with asink, the appearance of water in the sink will show the attendant thatthe proper amount of water has been supplied; if the conduit isconnected with a permanent drain, the gurgling of the water in the drainwill constitute an audible signal that the proper quantity of water hasbeen supplied; or a suitable signal device may be provided for thispurpose, such as an electromagnetically operated bell or incandescentlamp placed in the energizing circuit of the device 37.

When the attendant is informed that the proper quantity of water hasbeen supplied to the vat, the fluid supply will be turned off. Afterthis, the current demand on the motor will not be sufficient to operatethe valve 27 to its open position.

After the correct quantity of water has been supplied to the vat, theimpeller 12 may be operated to hurl the accumulated Water upwardly andoutwardly through the dish-supporting racks in the vat as long asdesired so as to eiTect a thorough cleansing action on the dishes.

When the washing operation has been completed, the drain valve will beopened by means of the operating rod 36a, and the operation of the pump30 will be continued until after all of the water has been withdrawnfrom the vat; then the switch 42 may be opened to deenergize the motor13.

If it is desired to rinse the dishes, water will be supplied to thereaction spray device 24 which will function, as before, to spray thewater over the dishes. In this case however, the drain valve 27 will beopened so that the water supplied to the vet can flow directly to thedischarge pump 30.

.It will be observed that by reason or the balanced construction of thethermostatic bars 44 and 45 that after the first operation, that is,after the thermostatic bar 44 has operated to close the contacts 56 and60 and to open the contacts 57 and 62, all subsequent operations will beapproximately twice as fast due to the fact that at the same time thatthe bar 44 is cooling, the bar 45 will be heated up so as to enhance theopening of the contacts and, hence, to increase the speed of the openingof the contacts 56 and 60, and the closure of the contacts 57 and 62.This provides a very sensitive and accurate control of the drain valve2'7.

In Fig. 5, a modified form of thermostat structure is shown. This formis arranged in substantially the same fashion as the thermostat of theabove mentioned Simmons patent.

In Fig. 5, the impeller driving motor is electrically connected with asuitable electrical supply source 81 through a controlling switch 82,.The armature circuit of the motor, as shown, is arranged to include thebi-metallic bar 83 of the thermostat. Bearing on the bi-metallic 'bar 83is a suitable U-shaped resilient member 84, one arm of which bears onthe bi-metallic bar and the other arm of which bears on a fixed pivot85. A suitable switch arm 86 is carried by the base of the U-shapedspring member, and this switch arm controls suitable contacts 87. Thesecontacts are included in the energizing circuit of the operating coil ofan electro-magnetic. device 88 which is arranged to operate the drainvalve to its open position. The drain valve is moved to its closedposition by means of a spring 91, and the valve is provided with amanually operable'lever 92, whereby it may be moved manually between itsopen and closed positions.

In the operation of this form of the invention when water is supplied tothe vat and as the load upon the impeller motor increases by virtue ofthe fact that additional fluid is being supplied, the thermostatic bar83 will be heated up and, upon the occurrence of a predermined maximumtemperature, i. e., upon the occurrence of a predetermined maximum loadon the impeller the thermostat will operate to close the contacts 87 soas to energize the electro-magnetic device 88. As before, this device 88thereupon will open the drain valve 90 and, as a result, water will flowfrom the vat to the drain. This withdrawal of fluid from the vat willreduce the load upon the impeller and on the motor, and the thermostaticbar 83 will cool; upon the occurrence of a predetermined minimum load inthe vat, i. e., when the bar 83 cools to a predetermined minimumtemperature, it will operate to open the contacts 87 and thereby eiIectthe closure of the drain valve 90. In this manner, the system willoperate to measure a predetermined quantity of fluid that is allowed toaccumulate in the vat.

In Fig. 6, still another modified form of the invention is shown whereinthe drain valve for the vat is eliminated and in its place a drain pumpis provided. As shown, the vat is provided with a drain port 101, whichcommunicates with the intake of a suitable pump 102. The pump dischargesinto a drain conduit 103. In this form, as before, water is supplied tothe vat through conduits 104 which carry fluid from a supply -conduit105 to a reaction spray device 106. The washing operation is effected bymeans of a suitable impeller 107, which is driven by means of anelectric motor 108.

The drainage pump 102 is driven by means of a motor 110. In this form ofthe invention, the motor is controlled to pump water from the vat uponthe occurrence of a predetermined maximumload on the impeller drivingmotor 108 and to cease operating when the load upon the impeller motor108 is reduced to a predetermined minimum value.

The motor 110 is controlled by means of a temperature responsive deviceof identically the same construction as the temperature responsivedevice 43 of Figs. 1, 2, 3, and 4. As shown diagrammatically in Fig. 7,this temperature responsive device comprises bi-metallic thermostat bars111 and 112, arranged as are the bars 44 and 45 of Figs. 2 and 3.Bearing on these bars is a resilient spring 113, similar to the spring50 of the above mentioned figures. The spring 113 carries a switch arm114, which operates a resilient contact arm 115 to control fixedcontacts 116 and a fixed contact 117, all arranged in identically thesame fashion as are the corresponding elements of the thermostat ofFigs. 2 and 3.

As shown in Fig. 7, one side of the motor 108 is electrically connectedwith the lower conductor of a suitable source of electrical supply 118by means of a conductor 120, while the other side of the motor iselectrically connected to one terminal of the bi-metallic bar 111through a conductor 121 and to one terminal of the other bimetallic bar112 through a conductor 122. The other terminal of the bi-metallic bar111 is electrically connected with the contact 117, and this contact iselectrically connected with the upper conductor of the supply source 118through the arm 115 and a conductor 123.

One terminal of the pump motor 110, as shown, is electrically connectedwith the lower conductor of the supply source 118 through the conductor120, while the other terminal of the motor 110 is electrically connectedwith the lower of the thermostat terminals 116 through a suitable switch124. The other terminal 116 is electrically connected with one terminalof the bi-metallic bar 112. The motor 110 may be connected directly withthe upper supply conductor through a conductor 124a and the conductor123 by moving the switch 124 to a second controlling position shown indotted lines in Fig. 7.

A suitable controlling switch 125 is interposed in the conductorsbetween the supply source 118 and the motor.

In the operation of this form oi the invention, it will be understoodthat switch 12 will be closed to start the apparatus andwhen this switchis closed, the motor 108 will be connected to the source of supplythrough the bi-metallic bar 111. Fluid may now be supplied to the vat.As the load on the motor increases by the water that is fed to the vat,the bar 111 will be heated and eventually the bi-metallic bar 111 willbe heated to such a temperature that it will operate to close thecontacts 116 and to open contact 117. This operation will connect theimpeller motor 108 to the supplysource 118 through the bimetallic bar112 and will efiect the energization of the pump driving motor 110through the lower one of the closed contacts 116. As previously pointedout, this motor 110 thereupon will operate the pump 102 to withdrawwater from the vat and force it into the drain conduit 103. Eventually,the bi-metallic bar 112 will be heated to such a temperature that itwill operate to reclose the contact 117 and to open the contacts 116.This operation will deenergize the pump motor 110. I1 the supply sourcehas not been turned off, the load imposed upon the motor 108 willincrease to such a value that again the motor 110 will be energized soas to withdraw water from the vat. In this manner, the pump motor 110will be controlledto allow but a predetermined quantity of fluid toremain in the vat.

If desired, suitable audible, or visible signals or both, may beprovided to warn the attendant when the pump is operating and, hence,when the proper quantity of water has been supplied to the vat. For thispurpose, a suitable incandescent lamp 126 or a suitable bell 127 or bothof these members may be connected in the system, as shown in Fig. '7, sothat when the pump is operating, the lamp and bell will be energized.When this signal is given, the attendant will turn oil? the water. Itwill be understood that after the water supply has been shut 011 and thepump 110 subsequently ceases to operate due to operation of thethermostat to close the contact 117 and to open the contacts 116, thethermostat will not function again to reenergize the motor 110 towithdraw any more water from the vat. This is because the currentdemanded by the impeller motor 108 will not be sufllcient to operate thethermostat to reenergize the motor 110.

When it is desired to drain the vat the switch 124 will be moved to itsdotted line controlling position (Fig. 7) so as to energize the drainpump. motor 110.

In Fig. 8, a modified form of the invention of Figs. 6 and 7 is shown;in this form the thermostatic structure, rather than being provided witha pair of bi-metallic bars is provided merely with a single iii-metallicbar, as is the thermostat of Fig. 5. As shown in Fig. 8, the singlebi-metallic bar 130 is arranged to be connected in series in thearmature circuit of the impeller 131 so as to respond directly to themagnitude of the armature current. Bearing on the bi-metallic bar 130 isa U-shaped spring member 132 arranged to move it quickly between itscontrolling positions. The U-shaped spring member 132 controls thebridging contact 133 that cooperates with fixed contacts 134. Thesecontacts 134, as shown, control the energizing circuit for the pumpmotor 135 so that when these contacts are closed. the pump motor will beenergized, whereas when the contacts are open, the pump motor willbedeenergized. A switch 136 is provided to controlthe energlzation ofthe pump motor 135.

A line switch 137 is provided to control the energization of theimpeller motor 131.

In operation, when the impeller driving motor 131 is operating and wateris being supplied to the vat, the temperature of the bar 130 willgradually increase as the load increases on the motor and, eventually,when a predetermined quantity of water has been supplied to the vat, thebi-metallic bar will operate to close the contacts 134. This operationwill energize the pump motor 135 through the thermostat contacts 134 andthe switch 136. This motor thereupon will operate to eflect thewithdrawal of fluid from the vat. This will decrease the load imposed onthe motor 131 and hence, will decrease its armature current. When apredetermined quantity of water has been withdrawn, the thermostat willhave cooled sufliciently to open the contacts 134 which operation willstop the operation of the pump. In this manner, the pump will becontrolled to allow a predetermined quantity of water to remain in thevat, which quantity will be the mean between the maximum and the minimumquantities at which the thermostat functions toenergize and todeenergize the pump motor. a

As in the case of Fig. 7, suitable signals, such as an incandescent lamp138 or a bell 139 or both of these devices may be connected in thecircuit of the pump motor 135, as shown, so that when this motor isenergized to withdraw water from the vat, the signal devices likewisewill be enersized.

When the signal is given, the attendant should shut off the watersupply. When this supply is shut ofl and the pump 102 has ceased tooperate, the current demanded by the impeller motor 131 will not besuflicient to cause the thermostat to function to reenergize the pumpmotor 135.

When it is desired to drain the vat, the switch 136 will be moved to itsdotted line controlling position (Fig. 8) which operation will efiectthe energization of the pump motor 135 independent" 1y 0! the impellermotor 131 and signal devices 138 and 139.

While I have shown particular embodiments of my invention, it will beunderstood 0! course that I do not wish to be limited thereto since manymodifications may be made, and I, therefore, contemplate by the appendedclaims to cover any such modifications as fall within the true spiritand scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. Washing apparatus comprising a vat, means for supplying a fluid tosaid vat, means for circulating the fluid in said vat, means fordraining said vat and control means for said draining means operablyassociated with said fluid circulating means to respond to a conditionof operation thereof that varies as the quantity of fluid in said vat ischanged so as to control said drainage means to drain fluid from saidvat when a predetermined quantity of fluid accumulates in said vat.

2. Dishwashing apparatus comprising a vat, means for supplying fluid tosaid vat, power means for circulating fluid in said vat, drain valvemeans tor said vat and means operably associated with said fluidcirculating means to respond to the load imposed thereon when operatingto circulate fluid in said vat controlling the operation of said drainvalve means to open to permit fluid to drain from said vat when saidload attains a predetermined maximum value and permit said valve meansto close when said load attains a predetermined minimum value.

3. Dishwashing apparatus comprising a vat, means for supplying fluid tosaid vat, power means for circulating fluid in said vat, a drain valvefor said vat, means biasing said drain valve to its closed position andmeans operably associated with said power means to respond to the loadimposed on said power means in circulating fluid in said vat controllingthe operation of said drain valve so as to open said valve when saidload attains a predetermined high value corresponding to a predeterminedmaximum quantity of fluid in said vat, and to allow said valve to closewhen said lead falls to a predetermined low value when a predeterminedquantity of fluid has drained from said vat.

4. Dishwashing apparatus comprising a vat provided with a drain port,means for supplying fluid to said vat, fluid circulating means in saidvat, a motor for operating said fluid circulating means, a valve forsaid drain port and means operably associated with said motor to respondto the load imposed on said motor by said fluid circulating meanscontrolling said drain valve to regulate the drainage of fluid Irom saidvat so as to allow but a predetermined maximum quantity of fluid toaccumulate in said vat.

5. Dishwashing apparatus comprising a vat provided with a drain port,means for supplying fluid to said vat, fluid circulating means in saidvat, a motor for operating said fluid circulating means, a drain valvefor said port and electroresponsive means for operating said drain valveconnected with said motor to respond to its load current which varies asthe quantityv of fluid in said vat varies to regulate the drainage offluid from said vat in accordance with the quantity of fluid therein soas to prevent the accumulation of more than a predetermined maximumquantity of fluid in said vat.

6. Dishwashing apparatus comprising a vat, fluid circulating means insaid vat, a motor for driving said fluid circulating means, means forsupplying said vat with washing fluid, means providing for thewithdrawal of washing fluid from said vat, means controlling said lastnamed means operably associated with said motor to respond. to the loadimposed thereon in circulating fluid in said vat so as to eflect thewithdrawalpf fluid when a predetermined maximum load is imposed on saidmotor and to stop the withdrawal of fluid when the load on said motorfalls to a predetermined low value.

'7. Dishwashing apparatus comprising a vat, means for supplying washingfluid to said vat, fluid circulating means in said vat, a motor foroperating said fluid circulating means, a drain valve for said vatcontrolling the drainage of fluid from said vat, an electro-responsivedevice controlling the operation of said drain valve to drain the fluidfrom said vat, an energizing circuit for said electro-responsive device,a switch controlling said energizing circuit and means operablyassociated with said motor to respond to its armature currentcontrolling said switch so as to control the energization of saidelectro-responsive device to open said drain valve when said armaturecurrent attains a predetermined maximum value and to allow said valve toclose when said armature current falls to a predetermined minimum value.

8. Dishwashing apparatus comprising a vat. means for supplying said vatwith a cleansing fluid, fluid circulating means in said vat, a motor fordriving said fluid circulating means, thermally responsive meanscontrolling the accumulation of fluid in said vat and means operablyassociating said thermally responsive means with said motor so that saidmeans is heated in accordance with the magnitude of the load imposed onsaid motor.

9. Dishwashing apparatus comprising a vat provided with a drain port,means for supplying a fluid to said vat, fluid circulating means in saidvat, a motor for driving said fluid circulating means, a valve for saiddrain port, means biasing said valve to its closed position, anelectromagnetic device controlling the operation 0! said valve to openit and a temperature responsive device operably associated with saidmotor so as to be heated by the armature current of said motorcontrolling the energization of said electromagnetic device to controlsaid drain valve to provide for the accumulation of a predeterminedmaximum quantity of water in said vat.

10. Dishwashing apparatus comprising a vat, means for supplying washingfluid to said vat, fluid circulating means in said vat, a motor foroperating said fluid circulating means, a drain valve for said vatcontrolling the drainage of fluid from said vat, an electro-responsivedevice controlling the operation of said drain valve to drain the fluidfrom said vat, an energizing circuit for said electro-responsive device,a switch controlling said energizing circuit and a thermostatic devicecomprising a thermal responsive member connected in the armature circuitof said motor so as to be heated in accordance with the magnitude ofsaid armature current controlling the operation of said switch so as tocontrol the energization of said electro-responsive device to open saiddrain valve when said armature current attains a predetermined maximumvalue and to allow said valve to close when said armature current fallsto a predetermined minimum value.

11. Dishwashing apparatus comprising a vat, means for supplying said vatwith fluid, means for circulating fluid in said vat, means forwithdrawing fluid i'rom said vat and means operably associated with saidfluid circulating means controlling the operation of said fluidwithdrawing means responsively to a condition of operation of said fluidcirculating means that varies as the quantity of fluid in said vatvaries so as to effect the withdrawal of fluid from said vat when apredetermined quantity of fluid accumulates in said vat.

12. Dishwashing apparatus comprising a vat, means for supplying said vatwith a cleansing fluid, fluid circulating means in said vat, a motor foroperating said fluid circulating means, a pump arranged to withdrawfluid from said vat and to pump it to a drain, and means operablyassociated with said motor to respond to the load imposed on said motorin driving said fluid circulating means controlling the operation ofsaid pump so as to remove fluid from said vat when a predeterminedquantity has been supplied to said vat and the load imposed on saidmotor attains a predetermined magnitude.

13. Dishwashing apparatus comprising a vat, means for supplying said vatwith a cleansing fluid, fluid circulating means in said vat, a motor foroperating said fluid circulating means, a pump arranged to withdrawfluid from said vat and to pump it to a drain, a motor for driving saidpump, an energizing circuit for said pump motor, means controlling saidenergizing circuit and a thermostatic device thermally responsive to theload current of said fluid circulating operating motor which varies asthe quantity of fluid in said vat is changed controlling the operationof said circuit controlling means so as to regulate the removal of fluidfrom said vat to allow but a predetermined quantity 0! fluid toaccumulate in said vat.

14. Dishwashing apparatus comprising a vat, means for supplying said vatwith a cleansing fluid, fluid circulating means in said vat, a motor foroperating said fluid circulating means, a pump arranged to withdrawfluid from said vat and to pump it to a drain, means operably associatedwith said motor to respond to the load imposed upon said motor indriving said fluid circulating means controlling the operation of saidpump so as to remove fluid from said vat when a predetermined quantityhas been applied to said vat and the load imposed on said motor attainsa predetermined magnitude, and means arranged .nsssr: H. CLARK.

